This invention relates to the manufacture of ice in bulk, and more particularly to apparatus for the manufacture, storage, and dispensing of large quantities of ice.
A variety of apparatus for use in the manufacture of large quantities of ice are now known to those skilled in the art. Representative ice-making machines are described in U.S. Pat. Nos. 3,074,252, 3,190,083, 3,246,481, 3,546,896, 3,587,241, and others. Commercial installations for the manufacture of ice, and particularly fragmented ice, generally include ice-making machines which actually form the ice and which are elevated above a bin, such as on a second floor of the installation. The ice makers discharge fragmented ice into a conveyor which in turn discharges the ice through an opening into the bin.
However, the automatic and sanitary handling of bulk, fragmentary ice once it is discharged into such a bin presents exceedingly difficult and specialized problems. Fragmented ice, when stored in a bin, can change characteristics during storage. For example, flakes of thin ice tend to break into smaller pieces akin to snow. Under certain temperature conditions, pieces of ice can fuse together. In addition, portions of ice in the lower part of a pile tend to fuse under the weight of a pile.
As a result of the foregoing, fragmented ice in bulk cannot be regarded as being made up of discrete particles and is not even a product having definite handling properties. Fragmentary ice in bulk has no definite angle of repose. Consequently, fragmentary ice in bulk form is virtually incapable of flowing out of a large bin by gravity.
The inability of fragmented ice in bulk to flow with gravity has been previously recognized, and the art has sought to employ a device known as an ice rake to facilitate the handling of ice. An ice rake is a type of drag conveyor which contacts the top of a pile of the ice and is maintained in contact therewith by a system of cables of which the rake is suspended. The ice rake has been found to be the only mechanism for use in the handling and storage of bulk fragmentary ice.
In my prior U.S. Pat. Nos. 3,842,993 and 3,797,267, there is disclosed an improved ice rake for use in large ice making systems. The ice rake there disclosed employs a sophisticated control system for activating the ice rake and for raising and lowering it to predetermined levels for selected time periods thereby to accurately control the movement of ice within the ice bin associated therewith. The present invention discloses a simplified and low cost ice rake for use in smaller systems. A large part of the cost of an ice rake system is in its electrical control system and by reducing the automatic capabilities of the system and by the use of certain mechanical inventions disclosed herein it is possible to produce a manually operated ice rake having a hoist with automatic leveling which is both effective and low in cost.
It is accordingly an object of the invention to provide an ice rake which is low in cost and effective for moving ice within a storage bin during loading and unloading of the bin.
Another object of the invention is to provide an ice rake having a manually operated hoist including an automatic leveling feature to maintain the ice rake in a substantially level condition regardless of the height of the ice piles across the bin.
Another object of the invention is to provide a low cost manual hoist for an ice rake which is counterbalanced to permit accurate control of the amount of pressure applied by the ice rake to the ice contained within the bin.
Other objects and advantages of the invention will be apparent from the remaining portion of the specification.